Microsoft Windows 8 has racked up more than 200 million license sales since its launch 15 months ago, which is about 40 million behind the first year sales of Windows 7. A Microsoft spokesperson announced the sales figures at a Goldman Sachs technology conference and it is the first official sales figures that Redmond has admitted.

To be fair, it might not be just that Windows 8 is being touted as Microsoft’s latest Vista, there has been a steady two-year decline in personal computer sales. Windows 8 was designed as a flexible new system that would work equally well on desktops PCs and touchscreen tablets, but it ended up alienating many traditional users.

More worryingly for Microsoft, the number of people actually using Windows 8 is persistently low. While many businesses technically have purchased Windows 8 licenses, few have installed it. According to tech statistics firm NetMarketShare, only about 11 percent of PC users worldwide are using Windows 8 or 8.1. Meanwhile, 48 percent are sticking with Windows 7 and 29 percent are still running Windows XP, which is more than a decade old.

Windows 7 is Microsoft's most successful operating system to date, selling more than 450 million licenses. It is probably telling that we have been early adopters of every version of Windows and have not even looked Windows 8.